The preparation of live samples, culture of cells, bacteria, viruses, other living materials, chemical compositions, etc. for microscopic examination presents technical problems in the preparation of the slide, both from a sealing perspective and from a hazard protection standpoint. The hazards presented by working with types of sample materials, such as live cells, live cultures of bacteria, viruses, or other biohazardous or chemically hazardous materials make it important to prevent the sample material from escaping from the slide into the outside environment, thereby potentially putting the microscopist and/or public and environment at risk.
The components of a conventional microscope slide include a slide base, a cover slip, and mounting media or a mountant to affix the sample material and the cover slip to the slide base. Microscope slides of living samples or samples in fluid media are conventionally prepared by simply mounting the sample material in a suitable mounting media, such as distilled water or glycerin, on the surface of the slide base. The cover slip is then placed on top of the sample material and the mounting media and is affixed to the slide base by the adhesive (surface tension) of the mounting media.
In order to obtain an accurate image of living material samples, it is essential that the slide base, cover slip, and the mountant are sterilized prior to the slide preparation process to prevent contamination of the sample. The slide preparation process is even more demanding when slides are prepared for use under very high magnifications and under special conditions including polarized light or dark field illumination. In these cases, various contaminating effects including very small contaminating particles, irregularities, and scratches in the slide, mountant, sample, or cover slip can obscure critical areas of the magnified image of the sample material. The microscopist could mistakenly interpret these contaminating effects in the sample image as being an actual part of the sample material. Conversely, the microscopist could mistakenly interpret that a real part of the sample material is an "artifact" and not part of the actual sample material. Accordingly, the clean and sterile condition of the slide, cover slip, and mounting media must be maintained while handling them during the mounting process.
In practice, the microscopist has to clean the slide base and cover slip and handle them carefully while loading a sample and/or mountant and while combining them to ensure that they are not damaged and that they and the sample and mountant is not contaminated. This process can be very difficult to achieve and is quite time consuming at best. Thus, the application of the mountant and the sample material involves a good deal of skill and attention on the part of the microscopist.
In addition, conventional microscopy slides can encounter problems when liquid sample materials are covered with a cover slip. For example, if too much sample material is placed on the slide base and the cover slip is placed on the sample material, the excess sample material will be squeezed out from under the cover slip, thereby possibly contaminating the user, the equipment, and the environment. This problem is caused by the generally incompressible nature of liquid within the sample material. To date, no practical solution has been found to address this problem.
A further disadvantage of conventional slides occurs when the sample material expands as a result of heating or chemical reaction. As a result of this expansion, the sample material may escape and contaminate the environment. To date, there has been no appropriate means or method to control the expansion of the sample material.
Further, there is a need for a convenient means and method for testing the effects of a palette of antibiotics, antiseptics and other chemical agents on bacteria, viruses, cells directly on the microscope slide.
Further, focusing of the objective of a microscope on the slide is a matter which requires careful and skilled adjustment of the fine focus and coarse focus of the microscope. This focussing process can be particularly difficult for people who are not experienced with microscope operation and are not able to judge the thickness of the prepared slide. For example, improper focussing of the objective can cause the objective lens to contact the slide, thereby damaging the objective and/or, more importantly, the prepared slide which can result in a breach in the cover slip or slide, permitting the sample material to escape therefrom. This is especially worrisome when the sample material is toxic or biohazardous as the sample can contaminate the microscope and the environment.